In dental treatment, there is a technique used in which a prosthesis such as an inlay or a crown is fabricated by using CAD/CAM. However, the tooth where the prosthesis is to be implemented has already been lost. Due to this, even in the CAD/CAM technique, it is desired to finely adjust the interference or separation with adjacent teeth in the oral cavity. As a result, an operator performs manual operations on a trial-and-error basis very often.
There exists a working method for working a dental prosthesis block into an inlay using a CAD/CAM apparatus. The working method includes dividing a working part to be worked on for an object shape into plural working areas, approximating the objective shapes on the working area basis, roughly working up to an enlarged shape or an offset shape, and finish working on the object shape based on the roughly worked shapes. By doing this, it becomes possible to reduce the influence of the size and the operations of a working jig, and to make a fine replica (see, for example, Japanese Patent No. 4464485).
Further, there exists a technique related to a method for generating a digital model of a dental prosthesis part such as an abutment. The generation method includes a step of evaluating scan data to detect at least a part of a shape of a dental prosthesis model, and a step of evaluating scan data to detect at least the position of a device that protects the dental prosthesis part (see, for example, Japanese Laid-open Patent Publication No. 2008-114079).
Further, there exists a technique providing a combination structure of a fixing part which fixes a tooth shaped part disposed at the position where a tooth is missing by contact while covering one or both of the side surfaces of adjacent teeth or the gingiva, and performs the protection of the tooth-missing area with aesthetic property and the prevention of disturbance after the implanting of the dental implant. When the CAD/CAM method is used, a more accurate prosthesis substitute can be formed by forming the prosthesis substitute based on digital data of the tooth-missing part and the surroundings. Thus, the formed dental prosthesis can suit the tooth-missing area, and the fixing property can be improved (see, for example, Japanese Laid-open Patent Publication No. 2010-269034).
There exists a technique which detects the interference not only between parts but also between various mechanisms located at the periphery of a printed board, between an apparatus and a part, and between the mechanism and the apparatus (see, for example, Japanese Patent No. 2609320).